drivers/acpi/processor_throttling.c

   1 /*
   2  * processor_throttling.c - Throttling submodule of the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *
  10  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or (at
  15  *  your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful, but
  18  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  *  General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License along
  23  *  with this program; if not, write to the Free Software Foundation, Inc.,
  24  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  25  *
  26  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/sched.h>
  33 #include <linux/cpufreq.h>
  34 #include <linux/proc_fs.h>
  35 #include <linux/seq_file.h>
  36
  37 #include <asm/io.h>
  38 #include <asm/uaccess.h>
  39
  40 #include <acpi/acpi_bus.h>
  41 #include <acpi/acpi_drivers.h>
  42 #include <acpi/processor.h>
  43
  44 #define PREFIX "ACPI: "
  45
  46 #define ACPI_PROCESSOR_CLASS            "processor"
  47 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  48 ACPI_MODULE_NAME("processor_throttling");
  49
  50 /* ignore_tpc:
  51  *  0 -> acpi processor driver doesn't ignore _TPC values
  52  *  1 -> acpi processor driver ignores _TPC values
  53  */
  54 static int ignore_tpc;
  55 module_param(ignore_tpc, int, 0644);
  56 MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
  57
  58 struct throttling_tstate {
  59         unsigned int cpu;               /* cpu nr */
  60         int target_state;               /* target T-state */
  61 };
  62
  63 #define THROTTLING_PRECHANGE       (1)
  64 #define THROTTLING_POSTCHANGE      (2)
  65
  66 static int acpi_processor_get_throttling(struct acpi_processor *pr);
  67 int acpi_processor_set_throttling(struct acpi_processor *pr,
  68                                                 int state, bool force);
  69
  70 static int acpi_processor_update_tsd_coord(void)
  71 {
  72         int count, count_target;
  73         int retval = 0;
  74         unsigned int i, j;
  75         cpumask_var_t covered_cpus;
  76         struct acpi_processor *pr, *match_pr;
  77         struct acpi_tsd_package *pdomain, *match_pdomain;
  78         struct acpi_processor_throttling *pthrottling, *match_pthrottling;
  79
  80         if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
  81                 return -ENOMEM;
  82
  83         /*
  84          * Now that we have _TSD data from all CPUs, lets setup T-state
  85          * coordination between all CPUs.
  86          */
  87         for_each_possible_cpu(i) {
  88                 pr = per_cpu(processors, i);
  89                 if (!pr)
  90                         continue;
  91
  92                 /* Basic validity check for domain info */
  93                 pthrottling = &(pr->throttling);
  94
  95                 /*
  96                  * If tsd package for one cpu is invalid, the coordination
  97                  * among all CPUs is thought as invalid.
  98                  * Maybe it is ugly.
  99                  */
 100                 if (!pthrottling->tsd_valid_flag) {
 101                         retval = -EINVAL;
 102                         break;
 103                 }
 104         }
 105         if (retval)
 106                 goto err_ret;
 107
 108         for_each_possible_cpu(i) {
 109                 pr = per_cpu(processors, i);
 110                 if (!pr)
 111                         continue;
 112
 113                 if (cpumask_test_cpu(i, covered_cpus))
 114                         continue;
 115                 pthrottling = &pr->throttling;
 116
 117                 pdomain = &(pthrottling->domain_info);
 118                 cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 119                 cpumask_set_cpu(i, covered_cpus);
 120                 /*
 121                  * If the number of processor in the TSD domain is 1, it is
 122                  * unnecessary to parse the coordination for this CPU.
 123                  */
 124                 if (pdomain->num_processors <= 1)
 125                         continue;
 126
 127                 /* Validate the Domain info */
 128                 count_target = pdomain->num_processors;
 129                 count = 1;
 130
 131                 for_each_possible_cpu(j) {
 132                         if (i == j)
 133                                 continue;
 134
 135                         match_pr = per_cpu(processors, j);
 136                         if (!match_pr)
 137                                 continue;
 138
 139                         match_pthrottling = &(match_pr->throttling);
 140                         match_pdomain = &(match_pthrottling->domain_info);
 141                         if (match_pdomain->domain != pdomain->domain)
 142                                 continue;
 143
 144                         /* Here i and j are in the same domain.
 145                          * If two TSD packages have the same domain, they
 146                          * should have the same num_porcessors and
 147                          * coordination type. Otherwise it will be regarded
 148                          * as illegal.
 149                          */
 150                         if (match_pdomain->num_processors != count_target) {
 151                                 retval = -EINVAL;
 152                                 goto err_ret;
 153                         }
 154
 155                         if (pdomain->coord_type != match_pdomain->coord_type) {
 156                                 retval = -EINVAL;
 157                                 goto err_ret;
 158                         }
 159
 160                         cpumask_set_cpu(j, covered_cpus);
 161                         cpumask_set_cpu(j, pthrottling->shared_cpu_map);
 162                         count++;
 163                 }
 164                 for_each_possible_cpu(j) {
 165                         if (i == j)
 166                                 continue;
 167
 168                         match_pr = per_cpu(processors, j);
 169                         if (!match_pr)
 170                                 continue;
 171
 172                         match_pthrottling = &(match_pr->throttling);
 173                         match_pdomain = &(match_pthrottling->domain_info);
 174                         if (match_pdomain->domain != pdomain->domain)
 175                                 continue;
 176
 177                         /*
 178                          * If some CPUS have the same domain, they
 179                          * will have the same shared_cpu_map.
 180                          */
 181                         cpumask_copy(match_pthrottling->shared_cpu_map,
 182                                      pthrottling->shared_cpu_map);
 183                 }
 184         }
 185
 186 err_ret:
 187         free_cpumask_var(covered_cpus);
 188
 189         for_each_possible_cpu(i) {
 190                 pr = per_cpu(processors, i);
 191                 if (!pr)
 192                         continue;
 193
 194                 /*
 195                  * Assume no coordination on any error parsing domain info.
 196                  * The coordination type will be forced as SW_ALL.
 197                  */
 198                 if (retval) {
 199                         pthrottling = &(pr->throttling);
 200                         cpumask_clear(pthrottling->shared_cpu_map);
 201                         cpumask_set_cpu(i, pthrottling->shared_cpu_map);
 202                         pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 203                 }
 204         }
 205
 206         return retval;
 207 }
 208
 209 /*
 210  * Update the T-state coordination after the _TSD
 211  * data for all cpus is obtained.
 212  */
 213 void acpi_processor_throttling_init(void)
 214 {
 215         if (acpi_processor_update_tsd_coord())
 216                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 217                         "Assume no T-state coordination\n"));
 218
 219         return;
 220 }
 221
 222 static int acpi_processor_throttling_notifier(unsigned long event, void *data)
 223 {
 224         struct throttling_tstate *p_tstate = data;
 225         struct acpi_processor *pr;
 226         unsigned int cpu ;
 227         int target_state;
 228         struct acpi_processor_limit *p_limit;
 229         struct acpi_processor_throttling *p_throttling;
 230
 231         cpu = p_tstate->cpu;
 232         pr = per_cpu(processors, cpu);
 233         if (!pr) {
 234                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Invalid pr pointer\n"));
 235                 return 0;
 236         }
 237         if (!pr->flags.throttling) {
 238                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling control is "
 239                                 "unsupported on CPU %d\n", cpu));
 240                 return 0;
 241         }
 242         target_state = p_tstate->target_state;
 243         p_throttling = &(pr->throttling);
 244         switch (event) {
 245         case THROTTLING_PRECHANGE:
 246                 /*
 247                  * Prechange event is used to choose one proper t-state,
 248                  * which meets the limits of thermal, user and _TPC.
 249                  */
 250                 p_limit = &pr->limit;
 251                 if (p_limit->thermal.tx > target_state)
 252                         target_state = p_limit->thermal.tx;
 253                 if (p_limit->user.tx > target_state)
 254                         target_state = p_limit->user.tx;
 255                 if (pr->throttling_platform_limit > target_state)
 256                         target_state = pr->throttling_platform_limit;
 257                 if (target_state >= p_throttling->state_count) {
 258                         printk(KERN_WARNING
 259                                 "Exceed the limit of T-state \n");
 260                         target_state = p_throttling->state_count - 1;
 261                 }
 262                 p_tstate->target_state = target_state;
 263                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PreChange Event:"
 264                                 "target T-state of CPU %d is T%d\n",
 265                                 cpu, target_state));
 266                 break;
 267         case THROTTLING_POSTCHANGE:
 268                 /*
 269                  * Postchange event is only used to update the
 270                  * T-state flag of acpi_processor_throttling.
 271                  */
 272                 p_throttling->state = target_state;
 273                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "PostChange Event:"
 274                                 "CPU %d is switched to T%d\n",
 275                                 cpu, target_state));
 276                 break;
 277         default:
 278                 printk(KERN_WARNING
 279                         "Unsupported Throttling notifier event\n");
 280                 break;
 281         }
 282
 283         return 0;
 284 }
 285
 286 /*
 287  * _TPC - Throttling Present Capabilities
 288  */
 289 static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
 290 {
 291         acpi_status status = 0;
 292         unsigned long long tpc = 0;
 293
 294         if (!pr)
 295                 return -EINVAL;
 296
 297         if (ignore_tpc)
 298                 goto end;
 299
 300         status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
 301         if (ACPI_FAILURE(status)) {
 302                 if (status != AE_NOT_FOUND) {
 303                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
 304                 }
 305                 return -ENODEV;
 306         }
 307
 308 end:
 309         pr->throttling_platform_limit = (int)tpc;
 310         return 0;
 311 }
 312
 313 int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
 314 {
 315         int result = 0;
 316         int throttling_limit;
 317         int current_state;
 318         struct acpi_processor_limit *limit;
 319         int target_state;
 320
 321         if (ignore_tpc)
 322                 return 0;
 323
 324         result = acpi_processor_get_platform_limit(pr);
 325         if (result) {
 326                 /* Throttling Limit is unsupported */
 327                 return result;
 328         }
 329
 330         throttling_limit = pr->throttling_platform_limit;
 331         if (throttling_limit >= pr->throttling.state_count) {
 332                 /* Uncorrect Throttling Limit */
 333                 return -EINVAL;
 334         }
 335
 336         current_state = pr->throttling.state;
 337         if (current_state > throttling_limit) {
 338                 /*
 339                  * The current state can meet the requirement of
 340                  * _TPC limit. But it is reasonable that OSPM changes
 341                  * t-states from high to low for better performance.
 342                  * Of course the limit condition of thermal
 343                  * and user should be considered.
 344                  */
 345                 limit = &pr->limit;
 346                 target_state = throttling_limit;
 347                 if (limit->thermal.tx > target_state)
 348                         target_state = limit->thermal.tx;
 349                 if (limit->user.tx > target_state)
 350                         target_state = limit->user.tx;
 351         } else if (current_state == throttling_limit) {
 352                 /*
 353                  * Unnecessary to change the throttling state
 354                  */
 355                 return 0;
 356         } else {
 357                 /*
 358                  * If the current state is lower than the limit of _TPC, it
 359                  * will be forced to switch to the throttling state defined
 360                  * by throttling_platfor_limit.
 361                  * Because the previous state meets with the limit condition
 362                  * of thermal and user, it is unnecessary to check it again.
 363                  */
 364                 target_state = throttling_limit;
 365         }
 366         return acpi_processor_set_throttling(pr, target_state, false);
 367 }
 368
 369 /*
 370  * _PTC - Processor Throttling Control (and status) register location
 371  */
 372 static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
 373 {
 374         int result = 0;
 375         acpi_status status = 0;
 376         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 377         union acpi_object *ptc = NULL;
 378         union acpi_object obj = { 0 };
 379         struct acpi_processor_throttling *throttling;
 380
 381         status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
 382         if (ACPI_FAILURE(status)) {
 383                 if (status != AE_NOT_FOUND) {
 384                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
 385                 }
 386                 return -ENODEV;
 387         }
 388
 389         ptc = (union acpi_object *)buffer.pointer;
 390         if (!ptc || (ptc->type != ACPI_TYPE_PACKAGE)
 391             || (ptc->package.count != 2)) {
 392                 printk(KERN_ERR PREFIX "Invalid _PTC data\n");
 393                 result = -EFAULT;
 394                 goto end;
 395         }
 396
 397         /*
 398          * control_register
 399          */
 400
 401         obj = ptc->package.elements[0];
 402
 403         if ((obj.type != ACPI_TYPE_BUFFER)
 404             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 405             || (obj.buffer.pointer == NULL)) {
 406                 printk(KERN_ERR PREFIX
 407                        "Invalid _PTC data (control_register)\n");
 408                 result = -EFAULT;
 409                 goto end;
 410         }
 411         memcpy(&pr->throttling.control_register, obj.buffer.pointer,
 412                sizeof(struct acpi_ptc_register));
 413
 414         /*
 415          * status_register
 416          */
 417
 418         obj = ptc->package.elements[1];
 419
 420         if ((obj.type != ACPI_TYPE_BUFFER)
 421             || (obj.buffer.length < sizeof(struct acpi_ptc_register))
 422             || (obj.buffer.pointer == NULL)) {
 423                 printk(KERN_ERR PREFIX "Invalid _PTC data (status_register)\n");
 424                 result = -EFAULT;
 425                 goto end;
 426         }
 427
 428         memcpy(&pr->throttling.status_register, obj.buffer.pointer,
 429                sizeof(struct acpi_ptc_register));
 430
 431         throttling = &pr->throttling;
 432
 433         if ((throttling->control_register.bit_width +
 434                 throttling->control_register.bit_offset) > 32) {
 435                 printk(KERN_ERR PREFIX "Invalid _PTC control register\n");
 436                 result = -EFAULT;
 437                 goto end;
 438         }
 439
 440         if ((throttling->status_register.bit_width +
 441                 throttling->status_register.bit_offset) > 32) {
 442                 printk(KERN_ERR PREFIX "Invalid _PTC status register\n");
 443                 result = -EFAULT;
 444                 goto end;
 445         }
 446
 447       end:
 448         kfree(buffer.pointer);
 449
 450         return result;
 451 }
 452
 453 /*
 454  * _TSS - Throttling Supported States
 455  */
 456 static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
 457 {
 458         int result = 0;
 459         acpi_status status = AE_OK;
 460         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 461         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 462         struct acpi_buffer state = { 0, NULL };
 463         union acpi_object *tss = NULL;
 464         int i;
 465
 466         status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
 467         if (ACPI_FAILURE(status)) {
 468                 if (status != AE_NOT_FOUND) {
 469                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
 470                 }
 471                 return -ENODEV;
 472         }
 473
 474         tss = buffer.pointer;
 475         if (!tss || (tss->type != ACPI_TYPE_PACKAGE)) {
 476                 printk(KERN_ERR PREFIX "Invalid _TSS data\n");
 477                 result = -EFAULT;
 478                 goto end;
 479         }
 480
 481         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
 482                           tss->package.count));
 483
 484         pr->throttling.state_count = tss->package.count;
 485         pr->throttling.states_tss =
 486             kmalloc(sizeof(struct acpi_processor_tx_tss) * tss->package.count,
 487                     GFP_KERNEL);
 488         if (!pr->throttling.states_tss) {
 489                 result = -ENOMEM;
 490                 goto end;
 491         }
 492
 493         for (i = 0; i < pr->throttling.state_count; i++) {
 494
 495                 struct acpi_processor_tx_tss *tx =
 496                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 497                                                       states_tss[i]);
 498
 499                 state.length = sizeof(struct acpi_processor_tx_tss);
 500                 state.pointer = tx;
 501
 502                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Extracting state %d\n", i));
 503
 504                 status = acpi_extract_package(&(tss->package.elements[i]),
 505                                               &format, &state);
 506                 if (ACPI_FAILURE(status)) {
 507                         ACPI_EXCEPTION((AE_INFO, status, "Invalid _TSS data"));
 508                         result = -EFAULT;
 509                         kfree(pr->throttling.states_tss);
 510                         goto end;
 511                 }
 512
 513                 if (!tx->freqpercentage) {
 514                         printk(KERN_ERR PREFIX
 515                                "Invalid _TSS data: freq is zero\n");
 516                         result = -EFAULT;
 517                         kfree(pr->throttling.states_tss);
 518                         goto end;
 519                 }
 520         }
 521
 522       end:
 523         kfree(buffer.pointer);
 524
 525         return result;
 526 }
 527
 528 /*
 529  * _TSD - T-State Dependencies
 530  */
 531 static int acpi_processor_get_tsd(struct acpi_processor *pr)
 532 {
 533         int result = 0;
 534         acpi_status status = AE_OK;
 535         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 536         struct acpi_buffer format = { sizeof("NNNNN"), "NNNNN" };
 537         struct acpi_buffer state = { 0, NULL };
 538         union acpi_object *tsd = NULL;
 539         struct acpi_tsd_package *pdomain;
 540         struct acpi_processor_throttling *pthrottling;
 541
 542         pthrottling = &pr->throttling;
 543         pthrottling->tsd_valid_flag = 0;
 544
 545         status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
 546         if (ACPI_FAILURE(status)) {
 547                 if (status != AE_NOT_FOUND) {
 548                         ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
 549                 }
 550                 return -ENODEV;
 551         }
 552
 553         tsd = buffer.pointer;
 554         if (!tsd || (tsd->type != ACPI_TYPE_PACKAGE)) {
 555                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 556                 result = -EFAULT;
 557                 goto end;
 558         }
 559
 560         if (tsd->package.count != 1) {
 561                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 562                 result = -EFAULT;
 563                 goto end;
 564         }
 565
 566         pdomain = &(pr->throttling.domain_info);
 567
 568         state.length = sizeof(struct acpi_tsd_package);
 569         state.pointer = pdomain;
 570
 571         status = acpi_extract_package(&(tsd->package.elements[0]),
 572                                       &format, &state);
 573         if (ACPI_FAILURE(status)) {
 574                 printk(KERN_ERR PREFIX "Invalid _TSD data\n");
 575                 result = -EFAULT;
 576                 goto end;
 577         }
 578
 579         if (pdomain->num_entries != ACPI_TSD_REV0_ENTRIES) {
 580                 printk(KERN_ERR PREFIX "Unknown _TSD:num_entries\n");
 581                 result = -EFAULT;
 582                 goto end;
 583         }
 584
 585         if (pdomain->revision != ACPI_TSD_REV0_REVISION) {
 586                 printk(KERN_ERR PREFIX "Unknown _TSD:revision\n");
 587                 result = -EFAULT;
 588                 goto end;
 589         }
 590
 591         pthrottling = &pr->throttling;
 592         pthrottling->tsd_valid_flag = 1;
 593         pthrottling->shared_type = pdomain->coord_type;
 594         cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
 595         /*
 596          * If the coordination type is not defined in ACPI spec,
 597          * the tsd_valid_flag will be clear and coordination type
 598          * will be forecd as DOMAIN_COORD_TYPE_SW_ALL.
 599          */
 600         if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&
 601                 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&
 602                 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {
 603                 pthrottling->tsd_valid_flag = 0;
 604                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
 605         }
 606
 607       end:
 608         kfree(buffer.pointer);
 609         return result;
 610 }
 611
 612 /* --------------------------------------------------------------------------
 613                               Throttling Control
 614    -------------------------------------------------------------------------- */
 615 static int acpi_processor_get_throttling_fadt(struct acpi_processor *pr)
 616 {
 617         int state = 0;
 618         u32 value = 0;
 619         u32 duty_mask = 0;
 620         u32 duty_value = 0;
 621
 622         if (!pr)
 623                 return -EINVAL;
 624
 625         if (!pr->flags.throttling)
 626                 return -ENODEV;
 627
 628         pr->throttling.state = 0;
 629
 630         duty_mask = pr->throttling.state_count - 1;
 631
 632         duty_mask <<= pr->throttling.duty_offset;
 633
 634         local_irq_disable();
 635
 636         value = inl(pr->throttling.address);
 637
 638         /*
 639          * Compute the current throttling state when throttling is enabled
 640          * (bit 4 is on).
 641          */
 642         if (value & 0x10) {
 643                 duty_value = value & duty_mask;
 644                 duty_value >>= pr->throttling.duty_offset;
 645
 646                 if (duty_value)
 647                         state = pr->throttling.state_count - duty_value;
 648         }
 649
 650         pr->throttling.state = state;
 651
 652         local_irq_enable();
 653
 654         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 655                           "Throttling state is T%d (%d%% throttling applied)\n",
 656                           state, pr->throttling.states[state].performance));
 657
 658         return 0;
 659 }
 660
 661 #ifdef CONFIG_X86
 662 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 663                                         acpi_integer * value)
 664 {
 665         struct cpuinfo_x86 *c;
 666         u64 msr_high, msr_low;
 667         unsigned int cpu;
 668         u64 msr = 0;
 669         int ret = -1;
 670
 671         cpu = pr->id;
 672         c = &cpu_data(cpu);
 673
 674         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 675                 !cpu_has(c, X86_FEATURE_ACPI)) {
 676                 printk(KERN_ERR PREFIX
 677                         "HARDWARE addr space,NOT supported yet\n");
 678         } else {
 679                 msr_low = 0;
 680                 msr_high = 0;
 681                 rdmsr_safe(MSR_IA32_THERM_CONTROL,
 682                         (u32 *)&msr_low , (u32 *) &msr_high);
 683                 msr = (msr_high << 32) | msr_low;
 684                 *value = (acpi_integer) msr;
 685                 ret = 0;
 686         }
 687         return ret;
 688 }
 689
 690 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 691 {
 692         struct cpuinfo_x86 *c;
 693         unsigned int cpu;
 694         int ret = -1;
 695         u64 msr;
 696
 697         cpu = pr->id;
 698         c = &cpu_data(cpu);
 699
 700         if ((c->x86_vendor != X86_VENDOR_INTEL) ||
 701                 !cpu_has(c, X86_FEATURE_ACPI)) {
 702                 printk(KERN_ERR PREFIX
 703                         "HARDWARE addr space,NOT supported yet\n");
 704         } else {
 705                 msr = value;
 706                 wrmsr_safe(MSR_IA32_THERM_CONTROL,
 707                         msr & 0xffffffff, msr >> 32);
 708                 ret = 0;
 709         }
 710         return ret;
 711 }
 712 #else
 713 static int acpi_throttling_rdmsr(struct acpi_processor *pr,
 714                                 acpi_integer * value)
 715 {
 716         printk(KERN_ERR PREFIX
 717                 "HARDWARE addr space,NOT supported yet\n");
 718         return -1;
 719 }
 720
 721 static int acpi_throttling_wrmsr(struct acpi_processor *pr, acpi_integer value)
 722 {
 723         printk(KERN_ERR PREFIX
 724                 "HARDWARE addr space,NOT supported yet\n");
 725         return -1;
 726 }
 727 #endif
 728
 729 static int acpi_read_throttling_status(struct acpi_processor *pr,
 730                                         acpi_integer *value)
 731 {
 732         u32 bit_width, bit_offset;
 733         u64 ptc_value;
 734         u64 ptc_mask;
 735         struct acpi_processor_throttling *throttling;
 736         int ret = -1;
 737
 738         throttling = &pr->throttling;
 739         switch (throttling->status_register.space_id) {
 740         case ACPI_ADR_SPACE_SYSTEM_IO:
 741                 ptc_value = 0;
 742                 bit_width = throttling->status_register.bit_width;
 743                 bit_offset = throttling->status_register.bit_offset;
 744
 745                 acpi_os_read_port((acpi_io_address) throttling->status_register.
 746                                   address, (u32 *) &ptc_value,
 747                                   (u32) (bit_width + bit_offset));
 748                 ptc_mask = (1 << bit_width) - 1;
 749                 *value = (acpi_integer) ((ptc_value >> bit_offset) & ptc_mask);
 750                 ret = 0;
 751                 break;
 752         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 753                 ret = acpi_throttling_rdmsr(pr, value);
 754                 break;
 755         default:
 756                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 757                        (u32) (throttling->status_register.space_id));
 758         }
 759         return ret;
 760 }
 761
 762 static int acpi_write_throttling_state(struct acpi_processor *pr,
 763                                 acpi_integer value)
 764 {
 765         u32 bit_width, bit_offset;
 766         u64 ptc_value;
 767         u64 ptc_mask;
 768         struct acpi_processor_throttling *throttling;
 769         int ret = -1;
 770
 771         throttling = &pr->throttling;
 772         switch (throttling->control_register.space_id) {
 773         case ACPI_ADR_SPACE_SYSTEM_IO:
 774                 bit_width = throttling->control_register.bit_width;
 775                 bit_offset = throttling->control_register.bit_offset;
 776                 ptc_mask = (1 << bit_width) - 1;
 777                 ptc_value = value & ptc_mask;
 778
 779                 acpi_os_write_port((acpi_io_address) throttling->
 780                                         control_register.address,
 781                                         (u32) (ptc_value << bit_offset),
 782                                         (u32) (bit_width + bit_offset));
 783                 ret = 0;
 784                 break;
 785         case ACPI_ADR_SPACE_FIXED_HARDWARE:
 786                 ret = acpi_throttling_wrmsr(pr, value);
 787                 break;
 788         default:
 789                 printk(KERN_ERR PREFIX "Unknown addr space %d\n",
 790                        (u32) (throttling->control_register.space_id));
 791         }
 792         return ret;
 793 }
 794
 795 static int acpi_get_throttling_state(struct acpi_processor *pr,
 796                                 acpi_integer value)
 797 {
 798         int i;
 799
 800         for (i = 0; i < pr->throttling.state_count; i++) {
 801                 struct acpi_processor_tx_tss *tx =
 802                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 803                                                       states_tss[i]);
 804                 if (tx->control == value)
 805                         return i;
 806         }
 807         return -1;
 808 }
 809
 810 static int acpi_get_throttling_value(struct acpi_processor *pr,
 811                         int state, acpi_integer *value)
 812 {
 813         int ret = -1;
 814
 815         if (state >= 0 && state <= pr->throttling.state_count) {
 816                 struct acpi_processor_tx_tss *tx =
 817                     (struct acpi_processor_tx_tss *)&(pr->throttling.
 818                                                       states_tss[state]);
 819                 *value = tx->control;
 820                 ret = 0;
 821         }
 822         return ret;
 823 }
 824
 825 static int acpi_processor_get_throttling_ptc(struct acpi_processor *pr)
 826 {
 827         int state = 0;
 828         int ret;
 829         acpi_integer value;
 830
 831         if (!pr)
 832                 return -EINVAL;
 833
 834         if (!pr->flags.throttling)
 835                 return -ENODEV;
 836
 837         pr->throttling.state = 0;
 838
 839         value = 0;
 840         ret = acpi_read_throttling_status(pr, &value);
 841         if (ret >= 0) {
 842                 state = acpi_get_throttling_state(pr, value);
 843                 if (state == -1) {
 844                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 845                                 "Invalid throttling state, reset\n"));
 846                         state = 0;
 847                         ret = acpi_processor_set_throttling(pr, state, true);
 848                         if (ret)
 849                                 return ret;
 850                 }
 851                 pr->throttling.state = state;
 852         }
 853
 854         return 0;
 855 }
 856
 857 static int acpi_processor_get_throttling(struct acpi_processor *pr)
 858 {
 859         cpumask_var_t saved_mask;
 860         int ret;
 861
 862         if (!pr)
 863                 return -EINVAL;
 864
 865         if (!pr->flags.throttling)
 866                 return -ENODEV;
 867
 868         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
 869                 return -ENOMEM;
 870
 871         /*
 872          * Migrate task to the cpu pointed by pr.
 873          */
 874         cpumask_copy(saved_mask, &current->cpus_allowed);
 875         /* FIXME: use work_on_cpu() */
 876         set_cpus_allowed_ptr(current, cpumask_of(pr->id));
 877         ret = pr->throttling.acpi_processor_get_throttling(pr);
 878         /* restore the previous state */
 879         set_cpus_allowed_ptr(current, saved_mask);
 880         free_cpumask_var(saved_mask);
 881
 882         return ret;
 883 }
 884
 885 static int acpi_processor_get_fadt_info(struct acpi_processor *pr)
 886 {
 887         int i, step;
 888
 889         if (!pr->throttling.address) {
 890                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
 891                 return -EINVAL;
 892         } else if (!pr->throttling.duty_width) {
 893                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling states\n"));
 894                 return -EINVAL;
 895         }
 896         /* TBD: Support duty_cycle values that span bit 4. */
 897         else if ((pr->throttling.duty_offset + pr->throttling.duty_width) > 4) {
 898                 printk(KERN_WARNING PREFIX "duty_cycle spans bit 4\n");
 899                 return -EINVAL;
 900         }
 901
 902         pr->throttling.state_count = 1 << acpi_gbl_FADT.duty_width;
 903
 904         /*
 905          * Compute state values. Note that throttling displays a linear power
 906          * performance relationship (at 50% performance the CPU will consume
 907          * 50% power).  Values are in 1/10th of a percent to preserve accuracy.
 908          */
 909
 910         step = (1000 / pr->throttling.state_count);
 911
 912         for (i = 0; i < pr->throttling.state_count; i++) {
 913                 pr->throttling.states[i].performance = 1000 - step * i;
 914                 pr->throttling.states[i].power = 1000 - step * i;
 915         }
 916         return 0;
 917 }
 918
 919 static int acpi_processor_set_throttling_fadt(struct acpi_processor *pr,
 920                                               int state, bool force)
 921 {
 922         u32 value = 0;
 923         u32 duty_mask = 0;
 924         u32 duty_value = 0;
 925
 926         if (!pr)
 927                 return -EINVAL;
 928
 929         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
 930                 return -EINVAL;
 931
 932         if (!pr->flags.throttling)
 933                 return -ENODEV;
 934
 935         if (!force && (state == pr->throttling.state))
 936                 return 0;
 937
 938         if (state < pr->throttling_platform_limit)
 939                 return -EPERM;
 940         /*
 941          * Calculate the duty_value and duty_mask.
 942          */
 943         if (state) {
 944                 duty_value = pr->throttling.state_count - state;
 945
 946                 duty_value <<= pr->throttling.duty_offset;
 947
 948                 /* Used to clear all duty_value bits */
 949                 duty_mask = pr->throttling.state_count - 1;
 950
 951                 duty_mask <<= acpi_gbl_FADT.duty_offset;
 952                 duty_mask = ~duty_mask;
 953         }
 954
 955         local_irq_disable();
 956
 957         /*
 958          * Disable throttling by writing a 0 to bit 4.  Note that we must
 959          * turn it off before you can change the duty_value.
 960          */
 961         value = inl(pr->throttling.address);
 962         if (value & 0x10) {
 963                 value &= 0xFFFFFFEF;
 964                 outl(value, pr->throttling.address);
 965         }
 966
 967         /*
 968          * Write the new duty_value and then enable throttling.  Note
 969          * that a state value of 0 leaves throttling disabled.
 970          */
 971         if (state) {
 972                 value &= duty_mask;
 973                 value |= duty_value;
 974                 outl(value, pr->throttling.address);
 975
 976                 value |= 0x00000010;
 977                 outl(value, pr->throttling.address);
 978         }
 979
 980         pr->throttling.state = state;
 981
 982         local_irq_enable();
 983
 984         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 985                           "Throttling state set to T%d (%d%%)\n", state,
 986                           (pr->throttling.states[state].performance ? pr->
 987                            throttling.states[state].performance / 10 : 0)));
 988
 989         return 0;
 990 }
 991
 992 static int acpi_processor_set_throttling_ptc(struct acpi_processor *pr,
 993                                              int state, bool force)
 994 {
 995         int ret;
 996         acpi_integer value;
 997
 998         if (!pr)
 999                 return -EINVAL;
1000
1001         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1002                 return -EINVAL;
1003
1004         if (!pr->flags.throttling)
1005                 return -ENODEV;
1006
1007         if (!force && (state == pr->throttling.state))
1008                 return 0;
1009
1010         if (state < pr->throttling_platform_limit)
1011                 return -EPERM;
1012
1013         value = 0;
1014         ret = acpi_get_throttling_value(pr, state, &value);
1015         if (ret >= 0) {
1016                 acpi_write_throttling_state(pr, value);
1017                 pr->throttling.state = state;
1018         }
1019
1020         return 0;
1021 }
1022
1023 int acpi_processor_set_throttling(struct acpi_processor *pr,
1024                                                 int state, bool force)
1025 {
1026         cpumask_var_t saved_mask;
1027         int ret = 0;
1028         unsigned int i;
1029         struct acpi_processor *match_pr;
1030         struct acpi_processor_throttling *p_throttling;
1031         struct throttling_tstate t_state;
1032         cpumask_var_t online_throttling_cpus;
1033
1034         if (!pr)
1035                 return -EINVAL;
1036
1037         if (!pr->flags.throttling)
1038                 return -ENODEV;
1039
1040         if ((state < 0) || (state > (pr->throttling.state_count - 1)))
1041                 return -EINVAL;
1042
1043         if (!alloc_cpumask_var(&saved_mask, GFP_KERNEL))
1044                 return -ENOMEM;
1045
1046         if (!alloc_cpumask_var(&online_throttling_cpus, GFP_KERNEL)) {
1047                 free_cpumask_var(saved_mask);
1048                 return -ENOMEM;
1049         }
1050
1051         cpumask_copy(saved_mask, &current->cpus_allowed);
1052         t_state.target_state = state;
1053         p_throttling = &(pr->throttling);
1054         cpumask_and(online_throttling_cpus, cpu_online_mask,
1055                     p_throttling->shared_cpu_map);
1056         /*
1057          * The throttling notifier will be called for every
1058          * affected cpu in order to get one proper T-state.
1059          * The notifier event is THROTTLING_PRECHANGE.
1060          */
1061         for_each_cpu(i, online_throttling_cpus) {
1062                 t_state.cpu = i;
1063                 acpi_processor_throttling_notifier(THROTTLING_PRECHANGE,
1064                                                         &t_state);
1065         }
1066         /*
1067          * The function of acpi_processor_set_throttling will be called
1068          * to switch T-state. If the coordination type is SW_ALL or HW_ALL,
1069          * it is necessary to call it for every affected cpu. Otherwise
1070          * it can be called only for the cpu pointed by pr.
1071          */
1072         if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
1073                 /* FIXME: use work_on_cpu() */
1074                 set_cpus_allowed_ptr(current, cpumask_of(pr->id));
1075                 ret = p_throttling->acpi_processor_set_throttling(pr,
1076                                                 t_state.target_state, force);
1077         } else {
1078                 /*
1079                  * When the T-state coordination is SW_ALL or HW_ALL,
1080                  * it is necessary to set T-state for every affected
1081                  * cpus.
1082                  */
1083                 for_each_cpu(i, online_throttling_cpus) {
1084                         match_pr = per_cpu(processors, i);
1085                         /*
1086                          * If the pointer is invalid, we will report the
1087                          * error message and continue.
1088                          */
1089                         if (!match_pr) {
1090                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1091                                         "Invalid Pointer for CPU %d\n", i));
1092                                 continue;
1093                         }
1094                         /*
1095                          * If the throttling control is unsupported on CPU i,
1096                          * we will report the error message and continue.
1097                          */
1098                         if (!match_pr->flags.throttling) {
1099                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1100                                         "Throttling Controll is unsupported "
1101                                         "on CPU %d\n", i));
1102                                 continue;
1103                         }
1104                         t_state.cpu = i;
1105                         /* FIXME: use work_on_cpu() */
1106                         set_cpus_allowed_ptr(current, cpumask_of(i));
1107                         ret = match_pr->throttling.
1108                                 acpi_processor_set_throttling(
1109                                 match_pr, t_state.target_state, force);
1110                 }
1111         }
1112         /*
1113          * After the set_throttling is called, the
1114          * throttling notifier is called for every
1115          * affected cpu to update the T-states.
1116          * The notifier event is THROTTLING_POSTCHANGE
1117          */
1118         for_each_cpu(i, online_throttling_cpus) {
1119                 t_state.cpu = i;
1120                 acpi_processor_throttling_notifier(THROTTLING_POSTCHANGE,
1121                                                         &t_state);
1122         }
1123         /* restore the previous state */
1124         /* FIXME: use work_on_cpu() */
1125         set_cpus_allowed_ptr(current, saved_mask);
1126         free_cpumask_var(online_throttling_cpus);
1127         free_cpumask_var(saved_mask);
1128         return ret;
1129 }
1130
1131 int acpi_processor_get_throttling_info(struct acpi_processor *pr)
1132 {
1133         int result = 0;
1134         struct acpi_processor_throttling *pthrottling;
1135
1136         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1137                           "pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
1138                           pr->throttling.address,
1139                           pr->throttling.duty_offset,
1140                           pr->throttling.duty_width));
1141
1142         if (!pr)
1143                 return -EINVAL;
1144
1145         /*
1146          * Evaluate _PTC, _TSS and _TPC
1147          * They must all be present or none of them can be used.
1148          */
1149         if (acpi_processor_get_throttling_control(pr) ||
1150                 acpi_processor_get_throttling_states(pr) ||
1151                 acpi_processor_get_platform_limit(pr))
1152         {
1153                 pr->throttling.acpi_processor_get_throttling =
1154                     &acpi_processor_get_throttling_fadt;
1155                 pr->throttling.acpi_processor_set_throttling =
1156                     &acpi_processor_set_throttling_fadt;
1157                 if (acpi_processor_get_fadt_info(pr))
1158                         return 0;
1159         } else {
1160                 pr->throttling.acpi_processor_get_throttling =
1161                     &acpi_processor_get_throttling_ptc;
1162                 pr->throttling.acpi_processor_set_throttling =
1163                     &acpi_processor_set_throttling_ptc;
1164         }
1165
1166         /*
1167          * If TSD package for one CPU can't be parsed successfully, it means
1168          * that this CPU will have no coordination with other CPUs.
1169          */
1170         if (acpi_processor_get_tsd(pr)) {
1171                 pthrottling = &pr->throttling;
1172                 pthrottling->tsd_valid_flag = 0;
1173                 cpumask_set_cpu(pr->id, pthrottling->shared_cpu_map);
1174                 pthrottling->shared_type = DOMAIN_COORD_TYPE_SW_ALL;
1175         }
1176
1177         /*
1178          * PIIX4 Errata: We don't support throttling on the original PIIX4.
1179          * This shouldn't be an issue as few (if any) mobile systems ever
1180          * used this part.
1181          */
1182         if (errata.piix4.throttle) {
1183                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1184                                   "Throttling not supported on PIIX4 A- or B-step\n"));
1185                 return 0;
1186         }
1187
1188         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d throttling states\n",
1189                           pr->throttling.state_count));
1190
1191         pr->flags.throttling = 1;
1192
1193         /*
1194          * Disable throttling (if enabled).  We'll let subsequent policy (e.g.
1195          * thermal) decide to lower performance if it so chooses, but for now
1196          * we'll crank up the speed.
1197          */
1198
1199         result = acpi_processor_get_throttling(pr);
1200         if (result)
1201                 goto end;
1202
1203         if (pr->throttling.state) {
1204                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1205                                   "Disabling throttling (was T%d)\n",
1206                                   pr->throttling.state));
1207                 result = acpi_processor_set_throttling(pr, 0, false);
1208                 if (result)
1209                         goto end;
1210         }
1211
1212       end:
1213         if (result)
1214                 pr->flags.throttling = 0;
1215
1216         return result;
1217 }
1218
1219 /* proc interface */
1220 #ifdef CONFIG_ACPI_PROCFS
1221 static int acpi_processor_throttling_seq_show(struct seq_file *seq,
1222                                               void *offset)
1223 {
1224         struct acpi_processor *pr = seq->private;
1225         int i = 0;
1226         int result = 0;
1227
1228         if (!pr)
1229                 goto end;
1230
1231         if (!(pr->throttling.state_count > 0)) {
1232                 seq_puts(seq, "<not supported>\n");
1233                 goto end;
1234         }
1235
1236         result = acpi_processor_get_throttling(pr);
1237
1238         if (result) {
1239                 seq_puts(seq,
1240                          "Could not determine current throttling state.\n");
1241                 goto end;
1242         }
1243
1244         seq_printf(seq, "state count:             %d\n"
1245                    "active state:            T%d\n"
1246                    "state available: T%d to T%d\n",
1247                    pr->throttling.state_count, pr->throttling.state,
1248                    pr->throttling_platform_limit,
1249                    pr->throttling.state_count - 1);
1250
1251         seq_puts(seq, "states:\n");
1252         if (pr->throttling.acpi_processor_get_throttling ==
1253                         acpi_processor_get_throttling_fadt) {
1254                 for (i = 0; i < pr->throttling.state_count; i++)
1255                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1256                                    (i == pr->throttling.state ? '*' : ' '), i,
1257                                    (pr->throttling.states[i].performance ? pr->
1258                                     throttling.states[i].performance / 10 : 0));
1259         } else {
1260                 for (i = 0; i < pr->throttling.state_count; i++)
1261                         seq_printf(seq, "   %cT%d:                  %02d%%\n",
1262                                    (i == pr->throttling.state ? '*' : ' '), i,
1263                                    (int)pr->throttling.states_tss[i].
1264                                    freqpercentage);
1265         }
1266
1267       end:
1268         return 0;
1269 }
1270
1271 static int acpi_processor_throttling_open_fs(struct inode *inode,
1272                                              struct file *file)
1273 {
1274         return single_open(file, acpi_processor_throttling_seq_show,
1275                            PDE(inode)->data);
1276 }
1277
1278 static ssize_t acpi_processor_write_throttling(struct file *file,
1279                                                const char __user * buffer,
1280                                                size_t count, loff_t * data)
1281 {
1282         int result = 0;
1283         struct seq_file *m = file->private_data;
1284         struct acpi_processor *pr = m->private;
1285         char state_string[5] = "";
1286         char *charp = NULL;
1287         size_t state_val = 0;
1288         char tmpbuf[5] = "";
1289
1290         if (!pr || (count > sizeof(state_string) - 1))
1291                 return -EINVAL;
1292
1293         if (copy_from_user(state_string, buffer, count))
1294                 return -EFAULT;
1295
1296         state_string[count] = '\0';
1297         if ((count > 0) && (state_string[count-1] == '\n'))
1298                 state_string[count-1] = '\0';
1299
1300         charp = state_string;
1301         if ((state_string[0] == 't') || (state_string[0] == 'T'))
1302                 charp++;
1303
1304         state_val = simple_strtoul(charp, NULL, 0);
1305         if (state_val >= pr->throttling.state_count)
1306                 return -EINVAL;
1307
1308         snprintf(tmpbuf, 5, "%zu", state_val);
1309
1310         if (strcmp(tmpbuf, charp) != 0)
1311                 return -EINVAL;
1312
1313         result = acpi_processor_set_throttling(pr, state_val, false);
1314         if (result)
1315                 return result;
1316
1317         return count;
1318 }
1319
1320 const struct file_operations acpi_processor_throttling_fops = {
1321         .owner = THIS_MODULE,
1322         .open = acpi_processor_throttling_open_fs,
1323         .read = seq_read,
1324         .write = acpi_processor_write_throttling,
1325         .llseek = seq_lseek,
1326         .release = single_release,
1327 };
1328 #endif